Chamfers

Employing chamfers improves the appearance of components machined from square, hexagonal, octagonal, and other shaped bar stock, and minimizes burrs pushed up on the flat surfaces The chamfer shown in Drawing #10 extends from the outside corner of the hexagon to a circle inscribed within the flats and results in the most burr-free part.

Designate a diameter and an angle when specifying a chamfer for hex, square, or octagonal bars. The chamfer diameter should be at least .030" smaller than the distance between the flats.

A chamfer or countersink for a thread should be at least .015" smaller than the minor diameter for OD threads and at least .015" larger than the major diameter for ID threads. This chamfer will result in burr-free threads.